If you notice the TPMS indicator light staying on for a few seconds after startup, that indicates proper function of the TPMS system. However, If the light stays on after that few seconds, the vehicle is trying to tell you that there could be an issue with the air pressure in one of your tires.
When the TPMS light is staying on without flashing, it means that one or more of the tires on the vehicle is underinflated by 25% of the pressure listed on the door placard. This could be the spare tire, too so when you go to check the tire pressure after the TPMS light starts glowing, also check the spare.
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If, conversely, the TPMS light is flashing continuously for about 60 to 90 seconds, that generally indicates that there is a fault within the tire pressure monitoring system itself. Further diagnosis of the tire pressure monitoring system is required.
Remember that both your vehicles owners manual and the tire pressure placard (found inside the drivers door jamb), are the authority on your vehicles ideal tire pressure. Check your tire pressures when the tires are cold as the friction of driving can cause the pressure to fluctuate. Dont inflate your tires to the pressure listed on the tire itself that is the maximum pressure for the tire.
If you are looking for more details, kindly visit TPMS Sensor Tool.